wined3d: Store the number of aux buffers in the context.
diff --git a/dlls/wined3d/wined3d_private.h b/dlls/wined3d/wined3d_private.h
index 652d86d..19ad58d 100644
--- a/dlls/wined3d/wined3d_private.h
+++ b/dlls/wined3d/wined3d_private.h
@@ -620,6 +620,7 @@
     HDC                     hdc;
     HPBUFFERARB             pbuffer;
     BOOL                    isPBuffer;
+    GLint                   aux_buffers;
 };
 
 typedef enum ContextUsage {